Green turtles (Chelonia mydas) are one of two nesting sea turtle species in the Mediterranean. Their nesting activity has a distribution limited to the eastern part of the basin (Kasparek et al. 2001). The main green turtle nesting beaches are located in Turkey (Kazanlı, Akyatan, and Samandağ) and Cyprus. A few nests are also found elsewhere in Turkey (Dalyan, Kumluca, Belek, Side-Kızılot, Göksu Delta, and Ağyatan), in addition to Lebanon, Israel, and northern Sinai. Samandağ beach, located in southeastern Turkey near the Syrian border (Fig. 1), is considered among the most important areas for green turtles in the Mediterranean, hosting 7% of the entire population (Kasparek et al. 2001).

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The importance of Samandağ beach for green turtle nesting activity has been confirmed by a monitoring program that recorded a nest density of 4.88, 22.4, and 22.4 nests per km in 2001, 2002, and 2003, respectively (Yalçın 2003; Yalçın-Özdilek and Sönmez 2003) and 126 nests in 2003 (Yalçın-Özdilek et al. 2004).

In the Mediterranean little is known about C. mydas population structure, distribution, and habitat utilization. In particular, the locations of juvenile developmental areas in the basin are still not clearly defined. The eastern part of the basin has been suggested to be a juvenile developmental area by different authors (Oruç et al. 1997; Laurent et al. 1996; Godley et al. 1998), whereas recent studies have reported two locations at more western areas: Lakonikos Bay, southern Peloponnese, Greece (Margaritoulis and Teneketzis 2001) and Fethiye beach, Turkey (Türkozan and Durmuş 2000).

Here, we examine stranding records of turtles found at Samandağ beach and discuss the possible location of a juvenile developmental area for the green turtle in the eastern Mediterranean (Fig. 1).

Methods

The entire length of Samandağ beach (14.5 km) was monitored on foot every day from 28 June to 15 September 2002. Stranded sea turtles found dead on the beach were recorded and identified to species. Curved carapace length (CCL) and curved carapace width (CCW) were measured with a flexible tape measure according to Bolten (1999).

Results

Twenty-eight stranded dead turtles were found along Samandağ beach during the 2002 nesting season (Table 1). Seventeen were collected at the beginning of the season, with 8 clearly old, probably stranded in previous years. An additional 11 turtles stranded during the season. Twenty-two (78.6%) were identified as C. mydas, with CCL ranging between 23.5 and 80 cm (mean = 40.6 ± 14.2 cm) (Fig. 2). One of them, with 35 cm CCL, had a stomach full of seagrass.

Table 1. Stranded sea turtles found on Samandağ beach, Turkey, in 2002.

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Discussion

Green turtles are believed to be omnivorous with a strong tendency to carnivory during their pelagic stage, and then shift to an herbivorous diet (Bjorndal 1997). Being benthic herbivores (Bjorndal 1997) they can find very little food in the open ocean and they presumably stay in the neritic environment. At the size of ca. 30–40 cm CCL, green turtles generally recruit to neritic developmental habitats (Musick and Limpus 1997) where they are known to have strong feeding site fidelity and sometimes become resident until they approach maturity (Musick and Limpus 1997; Limpus and Walter 1980). Meylan and Meylan (1999) noted that juvenile green turtles of 20–30 cm in carapace length are commonly found in shallow-water neritic habitats.

In the Mediterranean, it is assumed that juvenile green turtles feed on seagrasses such as Cymodocea nodosa, Zostera spp., Posidonia oceanica, Halophila stipulacea, and algae. In Cyprus, 3 drowned green turtle juveniles had been feeding exclusively on C. nodosa (Demetropoulus and Hadjichristophorou 1995).

The Turkish coastal area between Mersin and Yumurtalık is an area where juvenile green turtles can be suspected to forage. In fact, the Gulf of İskenderun was first cited by Gruvel (1933) (in Groombridge 1990) as frequented by turtles outside the nesting season, including adults, subadults, and smaller immature turtles. Successive observations from stranded turtles found during a survey along the Turkish coast (Baran and Kasparek 1989), suggested that green turtles reside in shallow water adjacent to their nesting beaches along the Çukurova region coast.

The frequent presence of juveniles in the Çukurova area has been confirmed by a recent study (Oruç et al. 1997), which showed that juveniles with CCL size ranging between 30 and 60 cm occur in the area and are mostly captured in winter. In addition, the physical characteristics of the coast in the Çukurova region (about 120 km long) and the sea characteristics within the 10-m isobath with an extension of 1.5–6 km offshore, support the hypothesis that this is a suitable area for green turtle foraging.

The size of stranded green turtles at Samandağ reported here suggests that juvenile C. mydas are probably foraging in the area. One was found with its stomach full of seagrass. Thus, C. mydas juvenile developmental habitat in the eastern Mediterranean may include areas around Samandağ beach. Research and conservation efforts should be focused on this area to help elucidate possible threats to juvenile sea turtles leading to strandings.